This grant supports the study of abnormal physiologic conditions and comparative diseases that are of interest in biomedical research. Current studies include the following: 1. Enterocolitis in Mesocricetus auratus. 2. Environmental effects on hepatic microsomal drug metabolism. 3. Intestinal enzyme changes due to disease and diet. Neoplasia in laboratory animals. 5. Evaluation of sexual dimorphism in androgeninsensitive mice.